A flashback arrestor is a piece of safety equipment a technician can attach to a system mixing oxygen with combustible fuel for welding and cutting applications. The oxy-fuel system, as it is known, is a very common one, and flashback, where fire travels back up into the system and causes serious damage or an explosion, is a known risk. Using a flashback arrestor can protect equipment, as well as operators, and there are a number of models people can choose from to meet their needs.
People can use a flashback arrestor to prevent flames from reaching a regulator or the gas supply itself. The device can work in a number of ways. Some slow and cool flame to below the ignition point, keeping people safe in the event of a flashback. Others will automatically turn the gas supply off when they detect flashback, so if flames do travel through the system, they won't have any gas to feed on. The operator can adjust or reset the flashback arrestor after the incident to resume normal work.
Dry systems usually have a flame trap mechanism to stop flame in its tracks. Wet systems use liquid to stop or slow the movement of flames in the oxy-fuel rig. The most suitable device for the application depends on the oxygen and gas mixture the technician is using and what kind of work she is doing. A jeweler, for instance, has different requirements than a bridge welder. The flashback arrestor also works as part of a larger network of safety systems, ranging from wearing protective gloves to prevent burns to using an appropriate regulator to precisely control the mix of gases.
In some workplaces, a flashback arrestor is required for all oxy-fuel equipment. Workers may get in trouble if they do not use the device, depending on the safety policies. Other shops strongly recommend the devices and may ask their safety officers to encourage people to use them, but do not require them. People working solo in their own shops must consider their personal safety when deciding how to set up their equipment.
The flashback arrestor is most useful when people properly maintain it. People must maintain their working rigs with care to make sure they do not create safety hazards. It is typical to periodically inspect all of the parts to see if they are properly fitted and functioning. Some people may break down individual parts for cleaning, oiling, and calibration, and a service technician can also perform this task.
By Mary McMahon
Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a About Mechanics researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.